Automotive refrigeration compressor module

ABSTRACT

An automotive refrigeration compressor module is provided of optimally minimum size for a given capacity and is of the reciprocating rectangular piston type. The piston is driven by a drive block within the piston mounted on the eccentric of a crankshaft. An internal counterbalance is mounted in the suction chamber to facilitate size reduction of the compression chamber and an external counterbalance is provided on the outer end of the crankshaft integrated with the drive clutch for the compressor. A dual module unit of twice the capacity of the single module is also provided. Both embodiments utilize refrigerant entrained oil for lubrication and include galleries in the crankshaft and drive block to effect complete circulation of the lubricant to all the moving parts. Insertable bearing shim construction is provided to preclude the need for close tolerance machining of adjacent major moving parts and to keep cost to a minimum.

United States Patent {19} on 3,871,793

Olson, Jr. Mar. 18, 1975 l l AUTOMOTIVE REFRIGERATION Primary Examiner-William L. Freeh COMPRESSOR MODULE Assistant Examiner-Richard Sher [76] Inventor: John W. Olson, Jr., 2723 National Attorney Agent or firm-BIN}, and Bush PL, G l d, T 75040 at an ex 57 ABSTRACT [22] Filed: 1973 An automotive refrigeration compressor module is [2]] Appl. No.: 429,635 provided of optimally minimum size for a given capac ity and is of the reciprocating rectangular piston type. The piston is driven by a drive block within the piston 417/273 417/3 mounted on the eccentric of a crankshaft. An internal Fieid 534 535 counterbalance 15 mounted in the suction chamber to 1 facilitate size reduction of the compression chamber and an external counterbalance is provided on the [56] References Cited outer end of the crankshaft integrated with the drive clutch for the compressor. A dual module unit of UNITED STATES PATENTS twice the capacity of the single module is also pro- 3,l74,436 3/1965 Wanner 417/273 vided. Both embodiments utilize refrigerant entrained 3,449,924 6/l969 3,456,874 7/[969 3,667,868 6/1972 3,685,923 8/1972 Hutchins et al.. 3,784.31 l/l974 Heidorn 417/273 Supmeier 417/319 X oil for lubrication and include galleries in the crankshaft and drive block to effect complete circulation of the lubricant to all the moving parts. lnsertable hearing shim construction is provided to preclude the need for close tolerance machining of adjacent major mov ing parts and to keep cost to a minimum.

17 Claims, 9 Drawing Figures FIJENTEU 1 8 3915 SAN 1 [If 5 N wt ENQNQ A 2 NW6 W/SN mm A I E 9/5 N pom FATENTEU 3.871.793

SHEU S [If 5 AUTOMOTIVE REFRIGERATION COMPRESSOR MODULE The invention relates to refrigerant compressors and more particularly. to such compressors which are especially well adapted for use in refrigerated automotive air conditioning systems.

BACKGROUND OF THE INVENTION Automotive air conditioning compressors. for optimum performance and utility, must be small in size. light in weight and low in cost while at the same time exhibiting rugged reliability and smoothness of operation over such speed ranges as from 800 to 8,000 revolutions per minute.

Bearing load capability and strength of the component parts of such compressors must be coordinated to withstand pumping pressures in the refrigerant gas or up to 500 pounds per square inch as well as shock loads resulting from the entry of liquid refrigerant into the compressor at speed ranges exceeding I000 revolutions per minute.

The requirement for small size is vital in this type of compresor in order that it may be mounted on the en gine of an automobile in the simplest and most straightforward manner and position to be driven by the engine with the least possible amount of brackets, braces, idler pulleys and other expensive secondary hardware.

It all of the foregoing is accomplished. the optimum result will be a compressor of the highest reliability and capacity for the least possible cost to the consumer.

SUMMARY OF THE INVENTION The compressor of the present invention is basically a compression module of the reciprocating single piston type having two compression strokes per revolution in each compression module.

In order to achieve the otimum size and shape for monunting the compression module to an engine and to provide a structural configuration which results in optimally minimum manufacturing costs, the present invention incorporates a rectangular compression member instead of the usual cylindrical pistons of other compressors.

This reciprocating compression member is provided with compression seals for the dual purpose of reducing gas leakage during the pumping stroke and to reduce the necessity for extreme accuracy in manufacturing tolerances in the compression module assembly.

Compensation for the vibration produced by the reciprocating action of the compression module is compensated to an optimum degree by a dual counterbalance configuration. One of the counterbalances is mounted on the suction chamber of the compression module on one end of the crankhaft and the other counterbalance is mounted externally or the module on the other end of the crankshaft in an integrated configuration with the driven plate of a convention magnetic clutch assembly.

The reciprocating compression member or rectangular piston is driven from the crankshaft via an internally disposed drive block. The clearance between the drive block and the internal drive block engaging surface of the compression member is determined by insertable flat steel rails or hearing plates of the required thickness to preclude the expensive necessity for machining close tolerances between the drive block and the compression member.

Proper running clearance between the compression member and the internal walls of the center case (compression chambers) of the compression module are also provided by insertable rails or hearing plates which also preclude the expensive of closely machined tolerances between component parts.

Since proper running clearances are essential for long life and low operating noise of the compression module, various thickness of rails or bearing plates are made readily available during production to achieve such clearances without the need for expensive closetolerance machining of component parts.

For lubrication of the compression module. oil entrained in the refrigerant is ever available to the compressor in short, high velocity automotive refrigeration systems. During the compression stroke, some of this oil is blown by the compresion seals and flows in vapor form from the center area of the compression member through the front roller bearing for the crankshaft into the shaft seal cavity, thence along an oil gallery in the crankshaft into the interior of the compression member and the suction chamber of the compressor. the said suction chamber containing a rear roller bearing for the crankshaft which is also lubricated by this oil flow. thus, all relatively moving and working surfaces of the compression module are lubricated.

An increase in capacity is accomplished by the present invention by a tandem arrangement of compression modules. For examples two such modules can be arranged on a common crankshaft with a common dual conterbalance system and a common centrally disposed suction chamber containing one of the counterweights. Lubrication is accomplished within each individual module as previously described.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a new and novel automotive refrigeration compression module of optimally minimum size, shape and cost but with optimally maximum ruggedness. reliability, capacity, versatility and smoothness of operation.

It is another object of the present invention to provide a new and novel automotive refrigeration compression module of the reciprocating type comprised of a combination of elements which preclude the necessity of closely machined tolerances between moving parts in order to achieve optimum operational qualities.

Still another object of the present invention is to provide a new and novel automotive refrigeration com pression module which can readily be combined with like modules to provide compressors of increased capacity.

These and other objects of the present invention will become more fully apparent with reference to the following specification and drawings which relate to presently preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a top plan view of the compression module of the present invention in partial cross-section;

FIG. 2 is a side elevation of FIG. I in a partial crosssection;

FIG. 3 is a front end view of FIGS. 1 and 2 in partial cross-section taken along line 3-3 of FIG. 2;

FIG. 4 is a rear end cross-section of FIGS. I and 2 taken along line 4-4 of FIG. 1;

FIG. 5 is a cross-section taken along line 55 of FIG. 4 and shows, additionally, the external counterbalance of the present invention;

FIG. 5A is a cross-sectional detail of the drive block of the present invention;

FIG. 6 is a cross-section taken along line 6-6 of FIG.

FIG. 7 is a side cross-section of a two-module embodiment of the present invention taken along line 7-7 of FIG. 8'. and

FIG. 8 is a central cross-section taken along line 8-8 of FIG. 7.

DETAILED DESCRIPTION OF THE DRAWINGS Referring first to FIGS. I, 2, 3 and 4, the compression module 10 of the present invention is shown as including an outer housing assembly 12 comprising a rear end plate or bell 12A, a central or compression chamber portion 128, a front end plate 12C and a shaft seal extension 12D extending coaxially from the front plate 12C.

The front end 14A of a crankshaft 14 extends outwardly from the shaft seal extension 12D through a set of front roller bearings I6 and a suitable shaft seal (not shown). The front roller bearings 16 are additionally shown in FIG. 5.

The central section 12B of the housing 12 defines a compression chamber I8 of rectangular volume in which is positioned a rectangular piston for reciprocation therein.

At the head of each end of the compression chamber 18 across the stroke path of the piston 20 is an intake or suction valve assembly 22 which is comprised of a perforated valve plate 22A, reed valves 22B and a compatibly perforated or bored reinforcing or valve retaining web 22C built into the central housing portion 128. The full configuration of the reed or flap valves 22B and the valve plate 22A from inside the compression chamber 18 is illustrated in FIG. 2, wherein two pairs of bifurcated reed or flap valves are shown riveted or otherwise affixed at 22D to the valve plate 22A.

Immediately adjacent the upper end of the compresion chamber I8 is an elongated series of discharge ports 24 arranged side by side across the side of the compression chamber 18 adjacent to the front cover plate IZC, the latter being formed internally in the provision of a discharge chamber 26.

The discharge ports 24 framed by a rectangular valve seat 24A on which an elongated discharge valve 248 of the flap or reed type is adapted to seat during the suction stroke of the one end of the piston 20 in the one end of the compression chamber 18 shown in FIG. 1.

The discharge valve 24B is anchored to the external wall 18A of the compression chamber 18 within the discharge chamber 26 in the front end plate 12C. by means of screws or rivets 24C engaged with extensions 24D of the said valve 245.

A duplicate suction valve assembly 22 and a discharge valve assembly 24 24D are disposed in like manner at the opposite end of the compression chamber 18.

The rectangular piston or compression member 20 is double ended and effects a suction stroke at one end of the chamber I8 while effecting a compression stroke at the other and vice-versa, during reciprocation thereof within the said chamber 18.

The suction valve assembly defines the head or end wall of opposite ends of the compression chamber 18 at positions inboard of the central housing portion 128.

A suction chamber 28 is provided within the rear bell housing portion 12A of the housing I2 and communicates with each suction inlet space 30 between each suction valve assembly 22 and the outer wall ofthe central housing portion I2B through laterally disposed suction ports 32 best shown in FIG. I for one end of the chamber I8. Both suction ports 32 are shown in FIG. 4.

An external connection for the discharge chamber 26 is illustrated in FIGS. 1 and 5 as a discharge port 26A through the wall of the front plate 12C of the housing 12.

A similar external connection (not shown) is provided through the wall of the rear bell housing portion 12A of the housing 12 for the suction chamber I8.

Referring jointly to FIGS. l, 4, 5 and 6 and with particular reference to FIG. 5, the crankshaft I4 of the compressor I0 is shown journalled in front and rear roller bearing assemblies I6 and I6A respectively. the said roller the said rear bearing assembly 16A being mounted in the central end wall ofthe bell housing 12A and supporting the rear end 145 of the crankshaft 14. The front roller beairng assembly I6 supports the crankshaft I4 at an intermediate portion I4C thereof as shown in FIG. 5.

An interior counterweight 34 is mounted. as by a key 34A. to that portion ofthe crankshaft I4 which extends through the suction chamber 28 such that rotation of the crankshaft 14 rotates the interior counterweight 34 within the suction chamber 28 in the rear bell housing 12A.

The crankshaft 14 has a crank or essentric portion intermediate the journalled portions 148 and 14C thereof and contained within the hollow interior 20A of the compression number or piston 20 and on which is mounted a sliding drive block 36.

As best shown in FIG. 6 the operating clearance between the drive block 36 and the interior walls of the piston 20 in the two directions of thrust which the drive block 36 imparts to the piston 20 is determined by opposed bearing shims or rails 38A and 388 which are fixed or mounted within the interior 20A of the piston 20 by any suitable means.

These rails 38A and 38B are readily stocked in vari ous thicknesses during the manufacture of the compressor 10 such that initially loose tolerances may be observed in fabricating the piston 20 and the drive block 36. This keeps the cost of the parts optimally low and still provides the means whereby the requisite close running tolerances can be effected. namely, merely inserting the proper shim thickness from the stock of rails 38A and 388.

Because of the compound orbital motion ofthe drive block 36 to assure quiet and smooth running characteristics of the piston 20 as it reciprocates in the compression chamber I8. close running tolerances are necessary at the top and bottom of the piston 20 as oriented in FIGS. 4. S and 6.

Here again, insertable bearing shims or rails 40A and 40B are removably mounted on the interior surfaces of the compression chamber I8 by any suitable means such that the relative manufactured tolerances between the chamber 18 and piston 20 can be loose.

As in the case of the drive block, this maintains an optimally low cost of the component parts without sacrificing the requisite close running clearances necessary for smoothness, strength, long life and reliability of the compressor.

The dual counterbalance assembly of the present invention is completed by the inclusion of an exterior or front counterweight 42F mounted on or integrated with the driven plate 42A of a magnetic clutch assembly 42, the said driven plate and front counterweight being mounted on the front or outer end 14A of the crankshaft 14. The clutch assembly 42 includes a drive plate 428 comprising a belt driven rotary pulley mounted on the exterior of the shaft seal housing extension 12D on an idler bearing assembly 42C and includes a magnetic field coil 42D for selectively engaging the driven and driving plates 42A-42B to actuate the compressor by rotating the crankshaft 14 as is known in the art.

The outer tip 14A of the crankshaft 14 is threaded in the embodiment shown to receive a lock nut 42E or other suitable retaining means to secure the clutch assembly 42 thereon.

The piston is provided at both ends thereof with peripheral compression seals 205 which because of the rectangular configuration comprise overlapping strip seals to effect optimum sealing as best shown in FIGS. 4 and 6.

Lubrication is provided with refrigerant entrained oil which blows by the compresion seals 208 during the compression stroke and circulates through an axially disposed oil gallery 44A in the crankshaft 14 communicating from the interior of the shaft housing 12D adjacent the front bearings 16 to the rear bearings 16A and the suction chamber 28; a branch oil gallery 44B through the eccentric portion 14D of the crankshaft connecting the axially disposed gallery 44A to a gallery 44C in the drive block 36; and through both the front and rear roller bearing assemblies I6 and 16A and the compression chamber 18 and suction chamber 28. These various entrained oil flow paths are shown by the small flow arrows in FIG. 5.

Also, as shown in FIG. 5, an O-ring backing and seal 46 is provided arond the crankshaft 14 where it passes through the dividing partition IZBl between the compression chamber 20 and the suction chamber 28.

M U LTIPLE MODU LE COMPRESSOR With reference to FIGS. 7 and 8, a two-module compressor 50 comprised of what is basically a pair of the compressor modules 10 of FIGS. 1-6 with a common central suction chamber and crankshaft will now be described.

A housing 52 is provided having first and second end plates 52Al and SZAZ, the latter mounting a shaft housing extension 52B and the former mounting a rear roller bearing housing 52C containing a rear roller bearing assembly 54 for the rear or inboard end of a cranshaft 56. A front roller bearing assembly 54A is mounted within the shaft housing 523.

The crankshaft 56 has first and second eccentric sections 56A and 56B contained, respectively, within first and second drive blocks 58A and 588 within first and second pistons 60A and 60B disposed in first and second compression chambers 62A and 62B in respective first and second central housing sections SZCI and 53C2.

A third central housing portion $2C3 defines a suction chamber 64 with an external suction connection 64A and houses within said suction chamber an internal counterweight 66 which is mounted such as by a bracket 66A and bolts 66B on a central connecting section 56C of the crankshaft 56 intermediate the eccentric sections 56A and 56B of the latter.

The end plates 52A2 and 52A] include discharge chambers 68A and 688, respectively, having respective external discharge connections 68A] and 68Bl. The chambers 68A and 68B communicate with the respective compresion chambers 60A and 608 through a plu rality of internal discharge parts and suitable valve means 68C as illustrated in FIG. 8 and as previously described in FIGS. 1-6 as bearing reference numerals 24. MA 24D.

The outboard end 56D of the crankshaft 56 will receive the same external couterweight and clutch assembly previously described with reference to FIG. 5 to complete the dual counterbalance system of the present invention in this two-module compressor 50.

Each of the drive blocks 58A and 58B are provided with the proper running clearances by insertable rails such as those shown at 70 in FIG. 8 and as previously described in FIGS. 1-6. Likewise, insertable rails or shims 72 are provided to constrain proper running clearances on the pistons 60A and 608 as shown in FIGS. 7 and 8 and as previously described in FIGS. l6.

Lubrication in this embodiment by the refrigerant en trained blow by mode and axially disposed oil galleries 74 and 76 are provided in the crankshafat from the shaft seal housing 528 to the suction chamber 64 and from the suction chamber 64 to the rear bearing assembly 54, respectively. A branch oil gallery 748 in the drive block 58A and another branch oil gallery 76A extends from the axial gallery 76 to an annular gallery 768 in the drive block 56B.

circulation of entrained lubricant is otherwise as previously described with reference to FIG. 5.

The central portion 56C of the crankshaft S6 is journalled on opposite sides of the suction chamber 64 by bushings or seals 78.

The compression strokes of the two pistons 60A and 60B are constrained by the crankshaft 56 to occur at 60, l20, 240 and 300' of rotation of the crankshaft 56 to provide smooth running characteristics, i.e.. a four-cylinder" effect rather than the two-cylinder" effect of FIGS. 1-6. Thus, as the operating capacity of the present invention is increased the timing of the strokes can be changed to avoid undue vibration and facilitate balancing by the dual counterweight system.

Referring again to FIGS. I and 5, the central housing section 12B is seen as comprising a spacer plate 128]. an enlarged central spacer plate 1282 and a third spacer plate I253, the first and third of which define the side walls of the compression chamber 18 and which include the discharge ports 24. The central plate 1282 defines the remaining confines of the compression chamber 18 and includes the mounting webs 22C of the suction valve assembly 22.

As indicated in FIGS. [-6, all of the various component parts of the housing 12 of the compressor 10 are ported to convey refrigerant and/or to receive assembly means such as the plurality of bolts 12E which hold the parts of the housing 12 together in an integral configuration.

With further reference to FIGS. and 6 and joint reference therewith to FIG. 5A, the drive block 36 is shown as a two-piece assembly 36A-36B with the sides thereto to be juxtaposed with the insertable bearing rails or shims 38A and 388 containing drilled oil ports 44C], 44C2 and 44C3, 4401, respectively. the said oil ports extending into communication with the annular oil gallery 44C in the crankshaft adjacent internal bore of the drive block 36.

Thus, refrigerant entrained oil is conveyed through the oil parts 44C} 44C4 from the annular oil gallery 44C to the working surfaces of the said drive block 36 and the bearing rails 38A, 388.

The stacked plate construction just described applies to the multiple module compressor 50 of FIGS. 7 and 8. Also, the lubrication and configuration of the drive blocks 58A and 588 include oil ports (not shown) which extend from adjacent the bearing rails 70 into communication with the annular oil galleries 74B and 768, respectively as previously described for the drive block 36.

Thus, with merely a minor number of parts changes, the single module compressor 10 can be readily converted to a dual module compresor 50 with twice the operating capacity of the compressor 10.

The parts changes in the embodiment shown are the suction chamber plates 52C3, the counterweight 66 and its mountings 66A-66B, the crankshaft 56, the rear end plate or bell 52A1 and one additional shaft bushing 78.

This high degree of adaptability to different capacities coupled with the low cost of parts and ease of manufacture effected by the removable bearing rails to selectively and rapidly provide proper running clearances during production result in a desirably dimple device of rugged construction, high strength and reliability at low cost and of optimally minimum size. Thus, the present invention satisfies a long felt need in the automotive air conditioning art.

What is claimed is:

l. A compressor for automotive refrigeration system comprising:

at least one compressor module having a housing,

said housing including a first housing section defining a substantially rectangular compression chamber bounded on each end by second and third housing sections defining discharge and suction chambers internally thereof. respectively;

a hollow substantially rectangular piston means in said compression chamber of a said module for reciprocation therein;

suction port means and discharge port means formed within said housing and interconnencting said compression chamber ofa said module at opposite ends thereof with said suction and discharge chambers, respectively;

suction valve means within said compression chamber of a said module at said opposite ends thereof opening and closing said suction port means in response to reciprocation of said piston means;

discharge valve means within said discharge chamber ofa said module opening and closing said discharge 65 port means in reverse order from said suction port means in response to reciprocation of said piston means;

a shaft seal extension on said housing;

a crankshaft extending through said housing and said piston means from a point external to said shaft seal extension to at least a point internal of said 5 suction chamber;

first bearing means in said second housing section and second bearing means journalling said crankshaft for rotation in said housing;

a first counterweight means mounted on said crankshaft for rotation therewith in said suction chamher;

a second counterweight means and integral drive clutch means mounted on the outboard end of said crankshaft externally of said shaft seal extension;

said crankshaft having an eccentric portion rotatable within said piston means; and

drive block means mounted on said eccentric portion within said piston means and imparting alternating thrust thereto to reciprocate said piston means in said compression chamber between said two ends thereof in response to rotation of said crankshaft means.

2. The invention defined in claim 1, wherein said drive clutch means further includes a driven clutch plate integrally mounted with said second counterweight means on said crankshaft and a pulley driven clutch plate and clutch activating means mounted for rotation on said shaft housing extension adjacent said driven clutch plate.

3. The invention defined in claim I, wherein said drive block and said piston means are machined to relatively loose tolerances with said interior of said piston means and said interior of said compression chamber. respectively, and

said compressor further includes insertable opposed bearing rails removably mounted within said interior of said piston means and said interior of said compression chamber providing selectively close running clearances between said drive block and said piston means and between said piston means and said compression chamber, thereby precluding the need for close initial tolerances between the major moving parts of said compressor.

4. The invention defined in claim I, wherein said compressor includes lubrication means for conveying refrigerant entrained lubricant to the moving parts thereof, said lubrication means including:

an axially disposed oil gallery in said crankshaft ex- 50 tending from said shaft extension housing to said suction chamber;

an annular oil gallery in said drive block around said eccentric portion of said crankshaft;

a branch oil gallery in said eccentric portion of said crankshaft interconnecting said axial and said annular galleries; and

oil port means formed in said drive block interconnecting said annular gallery with the juxtaposed surface of said drive block and said piston means.

5. The invention defined in claim 4, wherein said piston means further includes overlapping compression seals extending about the periphery of each of said piston means; and

wherein entrained lubricant blown by said seals during the compression stroke of said piston and ingested into said suction chamber circulates through said bearing means and said oil galleries to effect lubrication of said moving parts of said compressor.

6. The invention defined in claim 3, wherein said compressor includes lubrication means for conveying refrigerant entrained lubricant to the moving parts thereof, said lubrication means including:

an axially disosed oil gallery in said crankshaft extending from said shaft extension housing to said suction chamber;

an annular oil gallery in said drive block around said eccentric portion of said crankshaft;

a branch oil gallery in said eccentric portion of said crankshaft interconnecting said axial and said annular galleries; and

oil port means formed in said drive block interconnecting said annular gallery with the juxtaposed surfaces of said drive block and said insertable bearing rails within said piston means.

7. The invention defined in claim 3, wherein said piston means further includes overlapping compression seals extending about the periphery of each end of said piston means; and

wherein entrained lubricant blown by said seals during'the compression stroke of said piston and ingested into said suction chamber circulates through said bearing means and said oil galleries to effect lubrication of said moving parts of said compressor.

8. The invention defined in claim 2, wherein said compressor includes lubrication means for conveying refrigerant entrained lubricant to the moving parts thereof, said lubrication means including:

an axially disposed oil gallery in said crankshaft extending from said shaft extension housing to said suction chamber;

an annular oil gallery in said drive block around said eccentric portion of said crankshaft;

a branch oil gallery in said eccentric portion of said crankshaft interconnecting said axial and said annular galleries; and

oil port means formed in said drive block interconnecting said annular gallery with the juxtaposed surfaces ofsaid drive block and said piston means.

9. The invention defined in claim 8. wherein said piston means further includes overlapping compression seals extending about the periphery of each end of said piston means: and

wherein entrained lubricant blown by said seals during the compression stroke of said piston and ingested into said suction chamber circulates through said bearing means and said oil galleries to effect lubrication of said moving parts of said compressor.

10. The invention defined in claim 3, wherein said drive clutch means further includes a driven clutch plate integrally mounted with said second counter weight means on said crankshaft and a pulley driven clutch plate and clutch activating means mounted for rotation on said shaft housing extension adjacent said driven clutch plate;

said compressor includes lubrication means for conveying refrigerant entrained lubricant to the moving parts thereof, said lubrication means including:

an axially disposed oil gallery in said crankshaft extending from said shaft extension housing to said suction chamber;

an annular oil gallery in said drive block around said eccentric portion of said crankshaft; a branch oil gallery in said eccentric portion of said crankshaft interconnecting said axial and said an- 5 nular galleries; and

oil port means formed in said drive block interconnecting said annular gallery with the juxtaposed surfaces 'of said drive block and said insertable bearing rails within said piston means.

11. The invention defined in claim 10, wherein said piston means further includes overlapping compression seals extending about the periphery of each end of said piston means; and

wherein entrained lubricant blown by said seals during the compression stroke of said piston and ingested into said suction chamber circulates through said bearing means and said oil galleries to effect lubrication of said moving parts of said compressor.

12. The invention defined in claim 1, wherein said compressor includes at least two compressor modules having a common suction chamber in said third housing section;

a fourth housing section adjacent thereto defining a second compression chamber therein with a second said piston and drive block means;

a fifth housing section on the outboard side of said second compression chamber defining a discharge chamber therein for said second compression chamber;

a common crankshaft for said modules extending therethrough into said fifth housing section; and

said second bearing means journalling the inboard end of said crankshaft for rotation in said fifth housing section;

said crankshaft means having a said eccentric portion in each of said compression chambers on each of which is mounted one of said drive block means for reciprocating one of said pistons therein 13. The invention defined in claim 12, wherein said drive block and said piston means are machined to relatively loose tolerances with said interior of said piston means and said interior of said compression chamber. respectively, and

said compressor further includes insertable opposed bearing rails removably mounted within said interior of said piston means and said interior of said compression chamber providing selectively close running clearances between said drive block and said piston means and between said piston means and said compression chamber. thereby precluding the need for close initial tolerances between the major moving parts of said compressor.

14. The invention defined in claim 12, wherein said compressor includes lubrication means for conveying refrigerant entrained lubricant to the moving parts thereof, said lubrication means including:

axially disposed oil gallery means in said crankshaft extending from within said second and fifth housing sections to said suction chamber;

an annular oil gallery in each said drive block means around an adjacent said eccentric portion of said crankshaft;

a branch oil gallery in each said eccentric portion of said crankshaft interconnecting said axial and said annular galleries; and

1 l 12 oil port means formed in said drive block means inan annular oil gallery in each said drive block means terconnecting each said annular gallery with the around an adjacent said eccentric portion of said juxtaposed surfaces of said drive block and said pis crankshaft; ton means. a branch oil gallery in each said eccentric portion of 15. The invention defined in claim 14, wherein each 5 said crankshaft interconnecting said axial and said said piston means further includes overlapping comannular galleries; and pression seals extending about the periphery of each oil port means formed in said drive block interconend of said piston means; and necting each said annular gallery with the juxtawherein entrained lubricant blown by said seals durposed surfaces of said drive block and said inserting the compression stroke of said piston and inable bearing rails within said piston means. gested into said suction chamber circulates through 17. The invention defined in claim 13 wherein each said bearing means and said oil galleries to effect said piston means further includes overlapping comlubrication of said moving parts of said comprespression seals extending about the periphery of each sor. end of said piston means; and 16. The invention defined in claim 13, wherein said 15 wherein entrained lubricant blown by said seals durcompressor includes lubrication means for conveying ing the compression stroke of said piston and inrefrigerant entrained lubricant to the moving parts gested into said suction chamber circulates through thereof, said lubrication means including: said bearing means and said oil galleries to effect axially disposed oil gallery means in said crankshaft lubrication of said moving parts of said compresextending from within said second and fifth houssor. ing sections to said suction chamber; 

1. A compressor for automotive refrigeration system comprising: at least one compressor module having a housing, said housing including a first housing section defining a substantially rectangular compression chamber bounded on each end by second and third housing sections defining discharge and suction chambers internally thereof, respectively; a hollow substantially rectangular piston means in said compression chamber of a said module for reciprocation therein; suction port means and discharge port means formed within said housing and interconnencting said compression chamber of a said module at opposite ends thereof with said suction and discharge chambers, respectively; suction valve means within said compression chamber of a said module at said opposite ends thereof opening and closing said suction port means in response to reciprocation of said piston means; discharge valve means within said discharge chamber of a saId module opening and closing said discharge port means in reverse order from said suction port means in response to reciprocation of said piston means; a shaft seal extension on said housing; a crankshaft extending through said housing and said piston means from a point external to said shaft seal extension to at least a point internal of said suction chamber; first bearing means in said second housing section and second bearing means journalling said crankshaft for rotation in said housing; a first counterweight means mounted on said crankshaft for rotation therewith in said suction chamber; a second counterweight means and integral drive clutch means mounted on the outboard end of said crankshaft externally of said shaft seal extension; said crankshaft having an eccentric portion rotatable within said piston means; and drive block means mounted on said eccentric portion within said piston means and imparting alternating thrust thereto to reciprocate said piston means in said compression chamber between said two ends thereof in response to rotation of said crankshaft means.
 2. The invention defined in claim 1, wherein said drive clutch means further includes a driven clutch plate integrally mounted with said second counterweight means on said crankshaft and a pulley driven clutch plate and clutch activating means mounted for rotation on said shaft housing extension adjacent said driven clutch plate.
 3. The invention defined in claim 1, wherein said drive block and said piston means are machined to relatively loose tolerances with said interior of said piston means and said interior of said compression chamber, respectively, and said compressor further includes insertable opposed bearing rails removably mounted within said interior of said piston means and said interior of said compression chamber providing selectively close running clearances between said drive block and said piston means and between said piston means and said compression chamber, thereby precluding the need for close initial tolerances between the major moving parts of said compressor.
 4. The invention defined in claim 1, wherein said compressor includes lubrication means for conveying refrigerant entrained lubricant to the moving parts thereof, said lubrication means including: an axially disposed oil gallery in said crankshaft extending from said shaft extension housing to said suction chamber; an annular oil gallery in said drive block around said eccentric portion of said crankshaft; a branch oil gallery in said eccentric portion of said crankshaft interconnecting said axial and said annular galleries; and oil port means formed in said drive block interconnecting said annular gallery with the juxtaposed surface of said drive block and said piston means.
 5. The invention defined in claim 4, wherein said piston means further includes overlapping compression seals extending about the periphery of each of said piston means; and wherein entrained lubricant blown by said seals during the compression stroke of said piston and ingested into said suction chamber circulates through said bearing means and said oil galleries to effect lubrication of said moving parts of said compressor.
 6. The invention defined in claim 3, wherein said compressor includes lubrication means for conveying refrigerant entrained lubricant to the moving parts thereof, said lubrication means including: an axially disosed oil gallery in said crankshaft extending from said shaft extension housing to said suction chamber; an annular oil gallery in said drive block around said eccentric portion of said crankshaft; a branch oil gallery in said eccentric portion of said crankshaft interconnecting said axial and said annular galleries; and oil port means formed in said drive block interconnecting said annular gallery with the juxtaposed surfaces of said drive block and said insertable bearing rails within said piston means.
 7. The inveNtion defined in claim 3, wherein said piston means further includes overlapping compression seals extending about the periphery of each end of said piston means; and wherein entrained lubricant blown by said seals during the compression stroke of said piston and ingested into said suction chamber circulates through said bearing means and said oil galleries to effect lubrication of said moving parts of said compressor.
 8. The invention defined in claim 2, wherein said compressor includes lubrication means for conveying refrigerant entrained lubricant to the moving parts thereof, said lubrication means including: an axially disposed oil gallery in said crankshaft extending from said shaft extension housing to said suction chamber; an annular oil gallery in said drive block around said eccentric portion of said crankshaft; a branch oil gallery in said eccentric portion of said crankshaft interconnecting said axial and said annular galleries; and oil port means formed in said drive block interconnecting said annular gallery with the juxtaposed surfaces of said drive block and said piston means.
 9. The invention defined in claim 8, wherein said piston means further includes overlapping compression seals extending about the periphery of each end of said piston means; and wherein entrained lubricant blown by said seals during the compression stroke of said piston and ingested into said suction chamber circulates through said bearing means and said oil galleries to effect lubrication of said moving parts of said compressor.
 10. The invention defined in claim 3, wherein said drive clutch means further includes a driven clutch plate integrally mounted with said second counterweight means on said crankshaft and a pulley driven clutch plate and clutch activating means mounted for rotation on said shaft housing extension adjacent said driven clutch plate; said compressor includes lubrication means for conveying refrigerant entrained lubricant to the moving parts thereof, said lubrication means including: an axially disposed oil gallery in said crankshaft extending from said shaft extension housing to said suction chamber; an annular oil gallery in said drive block around said eccentric portion of said crankshaft; a branch oil gallery in said eccentric portion of said crankshaft interconnecting said axial and said annular galleries; and oil port means formed in said drive block interconnecting said annular gallery with the juxtaposed surfaces of said drive block and said insertable bearing rails within said piston means.
 11. The invention defined in claim 10, wherein said piston means further includes overlapping compression seals extending about the periphery of each end of said piston means; and wherein entrained lubricant blown by said seals during the compression stroke of said piston and ingested into said suction chamber circulates through said bearing means and said oil galleries to effect lubrication of said moving parts of said compressor.
 12. The invention defined in claim 1, wherein said compressor includes at least two compressor modules having a common suction chamber in said third housing section; a fourth housing section adjacent thereto defining a second compression chamber therein with a second said piston and drive block means; a fifth housing section on the outboard side of said second compression chamber defining a discharge chamber therein for said second compression chamber; a common crankshaft for said modules extending therethrough into said fifth housing section; and said second bearing means journalling the inboard end of said crankshaft for rotation in said fifth housing section; said crankshaft means having a said eccentric portion in each of said compression chambers on each of which is mounted one of said drive block means for reciprocating one of said pistons therein.
 13. The invention defined in claim 12, wherein said drive block and said piston means are machined to relatively loose tolerances with said interior of said piston means and said interior of said compression chamber, respectively, and said compressor further includes insertable opposed bearing rails removably mounted within said interior of said piston means and said interior of said compression chamber providing selectively close running clearances between said drive block and said piston means and between said piston means and said compression chamber, thereby precluding the need for close initial tolerances between the major moving parts of said compressor.
 14. The invention defined in claim 12, wherein said compressor includes lubrication means for conveying refrigerant entrained lubricant to the moving parts thereof, said lubrication means including: axially disposed oil gallery means in said crankshaft extending from within said second and fifth housing sections to said suction chamber; an annular oil gallery in each said drive block means around an adjacent said eccentric portion of said crankshaft; a branch oil gallery in each said eccentric portion of said crankshaft interconnecting said axial and said annular galleries; and oil port means formed in said drive block means interconnecting each said annular gallery with the juxtaposed surfaces of said drive block and said piston means.
 15. The invention defined in claim 14, wherein each said piston means further includes overlapping compression seals extending about the periphery of each end of said piston means; and wherein entrained lubricant blown by said seals during the compression stroke of said piston and ingested into said suction chamber circulates through said bearing means and said oil galleries to effect lubrication of said moving parts of said compressor.
 16. The invention defined in claim 13, wherein said compressor includes lubrication means for conveying refrigerant entrained lubricant to the moving parts thereof, said lubrication means including: axially disposed oil gallery means in said crankshaft extending from within said second and fifth housing sections to said suction chamber; an annular oil gallery in each said drive block means around an adjacent said eccentric portion of said crankshaft; a branch oil gallery in each said eccentric portion of said crankshaft interconnecting said axial and said annular galleries; and oil port means formed in said drive block interconnecting each said annular gallery with the juxtaposed surfaces of said drive block and said insertable bearing rails within said piston means.
 17. The invention defined in claim 13 wherein each said piston means further includes overlapping compression seals extending about the periphery of each end of said piston means; and wherein entrained lubricant blown by said seals during the compression stroke of said piston and ingested into said suction chamber circulates through said bearing means and said oil galleries to effect lubrication of said moving parts of said compressor. 